The present invention relates to a clutch release device including a sliding sleeve, particularly for motor vehicles; the sliding sleeve is made of sheet metal, and has a radial flange with opposite sides. One side faces the clutch and has contact surfaces for a radially displaceable clutch thrust bearing; the other side faces away from the clutch, and has contact surfaces for a clutch lever.
Such clutch release devices are already known in the art, and are disclosed, for example, in U.S. Pat. No. 3,963,106, Ernst et al, assigned to the assignee of the present application and have proven well in application. However, it was found that in the manufacture of sliding sleeves of sheet metal, with the contact surfaces for the clutch lever and for the clutch thrust bearing relatively far apart, the stress on the sheet metal is great, and that cracks may easily develop at the transition points between the flange and the cylindrical part.
It is therefore the object of the present invention to provide a sliding sleeve for a clutch release device of the above-described type, in such a way that any axial spacing, required between the contact surfaces of the clutch lever and the clutch thrust bearing to attain great freedom for the clutch lever, can be provided with ease and without overstressing the material. It is a further feature that the contact surfaces of the sliding sleeve must have great stiffness in the axial direction.